Dual-Electrically Configurable MoTe2/In2S3 Phototransistor toward Multifunctional Applications

Abstract

Photodetectors, essential for a wide range of optoelectronic applications in both military and civilian sectors, face challenges in balancing responsivity, detectivity, and response time due to their inherent unidirectional carrier transport mechanism. Multifunctional photodetectors that address these trade-offs are highly sought after for their potential to reduce costs, simplify system design, and surpass Moore’s Law limitations. Herein, we present a multimodal phototransistor based on a 2D MoTe₂/In₂S₃ heterostructure. Through dual electrical modulation employing bias voltage and gate voltage, we engineer the energy band to achieve switchable photoresponse mechanisms between photoconductive and photovoltaic modes. In photoconductive mode, the device exhibits a responsivity of 320 A/W and a specific detectivity of 1.2 × 10¹³ Jones. Meanwhile, in photovoltaic mode, it exhibits a light on/off ratio of 2 × 10⁵ and response speed of 0.68/0.60 ms. These capabilities enable multifunctional applications such as high-resolution imaging across various wavelengths, a conceptual optoelectronic logic gate, and dual-channel optical communication. This work makes an advancement in the development of future multifunctional optoelectronic devices.